I read the first post, did my research, then came back to post this, and read Rich's fine post about the tape issue.
I am a Journeyman Pipefitter, I seldom use Teflon tape. I have repaired too many systems where bits of tape were causing a mechanical breakdown. Most folks have not been trained on how to use Pipe Dope or Teflon tape.
First 3 threads.
Just coat the tapered pipe with some dope. I like 2 types, the Rectoseal Blue..the best. http://www.dultmeier.com/products/0.630.2128/9338
And white paste with Teflon mixed in it. I don't even carry Teflon tape on my truck. DO NOT use Teflon tape and Paste pipe dope together on a fitting.
Do not use tape or dope on compression fittings, they are not tapered and do no good.
Here is info I ripped off of Wicki:
Thread seal tape is most commonly found in the color white and is used in plumbing applications, but it is also available in various colors. White PTFE is single density, yellow is double density and pink is triple density. It is often used to correspond to color coded pipelines ((US, Canada, Australia & New Zealand) yellow for natural gas, green for oxygen, etc.). These color-codes for thread sealing tape were introduced by Bill Bentley of Unasco Pty Ltd in the 1970s. In the UK, tape is used from coloured reels, e.g. yellow reels for gas, green for potable water.
White - Used on NPT threads up to 3/8 inch.
Yellow - Used on NPT threads 1/2 inch to 2 inch, often labeled "gas tape".
Pink - Used on NPT threads 1/2 inch to 2 inch.
Green - Oil free PTFE used on oxygen lines and some specific medical gasses.
Copper - Contains copper granules and is certified as a thread lubricant but not a sealer.
Hazards
Over-use, or mis-application of thread tape may be a hazard. An excess amount of tape can prevent mating threads from fully engaging, therefore reducing the shear point of the threads. The use of thread-seal tape in addition to a pipe dope compound can also be dangerous, because it can become too much between the flanks of the threads. As the tape material is so soft, excess or overhangs may easily break off and form a foreign body contaminant that could jam a valve seat etc.
The Very BEST: You can buy it in a small tube, I carry them in all my toolboxes and in the truck.
http://www.rectorseal.com/product-da...u/dstrublu.htm